Increasing stocks of vacant housing deteriorating while the number of homeless grows. Not a very pretty picture and to my mind not a very rational outcome.

That's not what I'm advocating.

There's a surplus of housing. Let the prices of houses collapse. Then even poorer people can afford them and there's no need for a growing number of homeless people.

It's the government that has made house prices artificially high, and is trying to keep prices high with their bailout proposals.

The gov could buy defaulted houses and rent them to the needy. In the UK there used to be a huge social housing program. It sort of worked. If it had a weakness, it was that local councils [who administered it] also had a duty to house the homeless, so bad neighbours were always housed somewhere, rather than being shipped to the colonies etc. Same problem with US 'project' housing I suppose.

Then Reaganomics arrived..

The way I see it, the problems are that the vacant houses (and houses in general) are really big - much bigger than is appropriate for an average family.

I have a two-pronged solution for this.

1: Eliminate laws on minimum lot and house sizes and gut the laws against how many people can live in a house (100 sq. ft. per person seems like a good legal limit).

2: Have the government buy up a small number of houses and convert them into apartments (perhaps half a dozen low income units can be made from a single 3,000 square foot house). Transfer a substantial amount of money to the local government to pay for the extra infrastructure needed (larger water lines, more power plants, more telephone lines, etc). Finally either rent them out directly to the public or have them go condo with the stipulation that no one can simultaneously own one of these condos and any other piece of real estate at the same time.

I think you will see better results in having a single-family own the home and rent out bedrooms - the traditional boarder model. Though rarely seen today, this model still exists to a small degree, and certainly a converted bedroom, gameroom, or such could include a kitchenette, and have a private entrance.

I know, having rental properties myself in "owned" neighborhoods, that the owner-homes are much better taken care of than rental homes by the tenant (and maintained by the owner versus the landlord). Aggressive HOAs will fight any plan to revise usage, but the bigger problem is perception. These sorts of properties would do fine in a campus-area of town, but nobody wants to be the first to try it in an upscale neighborhood.

There are still many duplexes, though, and even dividing a house in half would work for many smaller families or single people. I'm encouraging my kids to buy duplexes as their first houses, and rent out the other half at a profit to reduce their expense. It's readily possible here, at least.